1. Field of the Invention
The present invention is related to a temperature detecting heater for an aquarium, and especially to a temperature detecting heater with an indicating structure for an aquarium with which a user can see whether the heating function of the temperature detecting heater is normal.
2. Description of the Prior Art
In an aquarium such as one for fishes, to prevent the temperature of water from being overly low, generally a temperature detecting heater is used to control the temperature of the water. A conventional temperature detecting heater mainly has a heating element and a temperature detecting element for detecting the temperature of water. When the temperature of water is overly low, the heating element is activated to emit heat to increase the temperature of the water; while if the temperature reaches a set value, the heating element is turned off to stop heat generating.
A heating element of a conventional temperature detecting heater is provided in a glass tube with an electric power indicating lamp. When the temperature detecting heater is turned on, the electric power indicating lamp is lightened to show that the temperature detecting heater is activated. Such a conventional structure is unable to let know whether the temperature detecting heater has been damaged or not, sometimes a danger of being overheated may happen, thereby improvement is required.